procomp 4" lift

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Feb 8, 2006 | 08:04 PM

SkylinePCG

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procomp 4" lift

Ive got an 02 f150 4x4, with a 5.4, ec/sb, 3.55 rearend, and was looking at replacing the stock tires on it, and considering a lift. Then I found a 4" procomp lift on ebay for $500. Ive already got a friend of mine, an ex-ford mechanic, on board to lead the install.

I was going to run BFG ATs, 315/70/17s on the stock 17x7.5 king ranch wheels. The truck is mostly street driven, but sees occasional swamp land (NOT mud bogs), and once a blue moon, a boat trailer.

Does anyone have any experience with the procomp lift? Is it worthwhile, or a complete turd? $500 is hard to beat for a suspension lift.

Feb 8, 2006 | 08:07 PM

stang3O2

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Sounds like a great deal for a 4" lift...my guess is a brand new set would be prob $1500 or so! But trust me, your gonna want gears after putting 35" tires on.

Feb 8, 2006 | 09:03 PM

SkylinePCG

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about the gears, H2's run around on the same 35's Id be using, and they run 4.10's, but the 6.0 makes a little more power than mine. WOuld I be better off running 4.56?

Feb 8, 2006 | 09:50 PM

stang3O2

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IMO yes 4.56. Ive got an 02 FX4 Ex-Cab 5.4L, pretty much same truck on 35s
315-75-16s. What you have to keep in mind is your 3.55 ratio with 35s is an actual effective ratio of prob around a 3.20. If you put a 4.56 gear with 35s, it actually puts you around a 4.10 ratio, same lines put a 4.10 gear in would be an actual around a 3.73 ratio. If you do a search on here for "Gear Calcs" you will find the formulas which will help you decide. Wind drag, height, and tire size all add up to changing your effective ratio. 35s and 4"s is alot for our pathetic 3.55 gears! Use this formula below to figure your "effective." Then what I did...just put a ratio of your choice say 4.10 or 4.56 in place of your 3.55s...do the same formula to see what your new ratio will actually be with your new gears! Do a search on here...you will find a bunch of good info!

Effective Ratio: (Stock tire size) divided by (New tire size) then multiply by your actual gear ratio equals effective ratio. (Stock) / (New) x Gear ratio= Effective

Feb 8, 2006 | 10:19 PM

SkylinePCG

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How does the power/mileage of your truck with the bigger tires and lower gears compare to when it was stock?

Feb 9, 2006 | 08:22 PM

stang3O2

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When I put 35s on with my stock 3.55s...power dropped, especially on takeoff, now its a dogg! SInce it changes your gear ratio...your tranny works much harder, and you run LOW rpms which the motor is constantly downshifting! For example: with my truck 35s 3.55 stock gears, I only run 1300rmps at 55mph at 70mph its only like 16-1700. Meaning, your rpms are really low for your power band. Mileage prob dropped an avg of 2mpg all around...I am definatlely in the process of putting gears in my truck real soon which will help especially with mileage in city driving, less downshifting, motor and tranny work much easier!

Feb 11, 2006 | 04:33 PM

tinman67

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From: St. Louis

Watch out with that lift kit not all lifts are made with the 5.4 in mind. If you use the wrong kit it will bash in your oil pan every time you hit a big bump. Check the mfr specs for the kit it will tell you if it is for the 4.6 or 5.4 as I understand it the 5.4 has a larger and lower riding oil pan and the sub frame of the lift kit bangs on the oil pan. I have a buddy with a useless 2000 Supercrew with 4" susp. and 3" body lift and 35" tires but when he hits a hard bump it smashes his oil pan.